1. Field of the Invention
The present invention relates to a frequency converter, and more particularly, to a frequency converter using a high-linearity amplifier.
2. Description of the Background Art
FIG. 1 illustrates a simplified block diagram of a conventional frequency converter.
The conventional frequency converter includes a local oscillator 101, a mixer 102 and an amplifier 103.
The local oscillator 101 articulately adjusts a voltage level of a voltage control oscillator and locks an output frequency to an intended frequency to oscillate a frequency for converting an intermediate frequency (IF) band into a radio frequency (RF) band.
The mixer 102 receives the oscillated frequency and the IF and, converts the oscillated frequency and the IF into a frequency at the RF band.
The amplifier 103 amplifies an output signal of the mixer 102.
The linearity of the mixer 102 is important to determine the linearity of the frequency converter. However, the linearity of the amplifier 103 is more important than that of the mixer 102 to determine the linearity of the frequency converter.
Hence, improving the linearity of the amplifier 103 is necessary to obtain high linearity of the frequency converter.